Ilker Ustoglu

Signaling System Solution for Urban Railways: Esenler Railway Depot

Abstract Among other transportation alternatives, rail transportation is of great importance in urban transportation. Especially in crowded cities such as Istanbul where over thirteen million people live in, the use of urban rail transportation is inevitable due to traffic jam at peak hours. In this study, information about the first urban light rail transit M1 railway line is given and the signaling solution proposed for Esenler railway depot which is established in M1 railway line is explained.

Polynomial Control Systems [Product Review]

124 IEEE CONTROL SYSTEMS MAGAZINE » AUGUST 2007 1066-033X/07/

Stabilizing constant controllers for two-input, two-output systems with reducible and irreducible characteristic equations

25.00©2007IEEE Polynomial Control Systems (PCS), a Mathematicabased toolbox released in July 2006 by Wolfram Research, Inc., expands the functionality of Wolframs Control System Professional Suite (CSPS) in a variety of ways. CSPS, which now consists of Control System Professional (CSP), Advanced Numerical Methods (ANM), and the new Polynomial Control Systems, was first released in the middle of 2003 [1] and is used by professionals and academicians working on control systems. PCS presents new tools for the modeling, analysis, and design of linear control systems described by polynomial matrix equations or matrices with rational polynomial entries [2]. Like its counterparts CSP and ANM, PCS follows an object-oriented methodology for analyzing and designing control systems. In this product review, some of the new tools provided by PCS are examined using tutorial examples and compared to similar tools available in Matlab. Specifically, the Control Systems Toolbox (version 6.1) [3] and Polynomial Control System Toolbox (PolyX—version 2.5) [4] of Matlab are used in comparisons. However, we point out that this review should not be considered as a comprehensive comparative study of PCS since our focus is to introduce some capabilities of PCS and, when feasible, contrast comparable capabilities of Matlab with PCS. Polynomial-based algorithms can provide useful insights for the analysis and design of multivariable systems. In the first part of the review, we examine several new system descriptions supported by PCS and the corresponding analysis tools. In the second part of the review, we focus on the design and synthesis of multivariable systems using PCS.

Internal model controller design via H∞ dynamic output feedback

This paper proposes a theoretical and practical approach for determining the stabilizing gain intervals for two-input, two-output (TITO) systems with a constant diagonal controller. Our main contribution is to present an algorithm which is more practical than the stabilizing methods that depend on the Nyquist stability criterion. Numerical examples illustrate the effectiveness of the proposed algorithm for TITO systems with reducible or irreducible characteristic equations.

Reliability assessment of fire safety systems in railway industry: a case study

This paper deals with internal model controller design via H ∞ dynamic output feedback for linear perturbed systems. The study proposes an internal model controller within the perspective of H ∞ dynamic output feedback, utilizing a linear matrix inequality based optimization algorithm. This proposed method is a synthesis of an internal model controller design that has different application fields, as reported in the literature, and an H ∞ dynamic output feedback controller, which has proven its success in several studies. The proposed controller attenuates disturbances, having bounded energies on controlled output. The originality of the work lies in the combination of two different approaches to obtain an optimal controller design algorithm. The liability and performance of the proposed method are illustrated via simulations, which are applied to a couple of benchmark problems.

Application of majority voting and consensus voting algorithms in N-version software

Within the framework of railroad transportation systems, there are currently system rooms where critical systems such as signalization are available. For the system to achieve an uninterrupted mode of operation, it is crucial to mitigate risks or hazards against the rooms and to ensure an acceptable level of safety. This study handles the protection of a system room, owned by Istanbul Ulaşım A.Ş. Edirnekapı branch, against an incident of fire as a safety-related system practice. Within this scope, the fire safety system has been handled as a safety-related system identified in IEC 61508. The safety integrity level required by the safety lifecycle for the relevant system has also been identified and safety functions that are required to be implemented have been put forth. Taking IEC 61508 as a reference for the functions, the required analyses have been performed through fault tree analysis. It has also been guaranteed that the relevant functions have met the required safety levels.

Introduction to Optimization

N-version programming is one of the most common techniques which is used to improve the reliability of software by building in fault tolerance, redundancy and decreasing common cause failures. N different equivalent software versions are developed by N different and isolated workgroups by considering the same software specifications. The versions solve the same task and return results that have to be compared to determine the correct result. Decisions of N different versions are evaluated by a voting algorithm or the so-called voter. In this paper, two of the most commonly used software voting algorithms such as the majority voting algorithm and the consensus voting algorithm are studied. The distinctive features of Nversion programming with majority voting and N-version programming with consensus voting are described. These two algorithms make a decision about the correct result on the base of the agreement matrix. However, if the equivalence relation on the agreement matrix is not satisfied it is impossible to make a decision. It is shown that the agreement matrix can be transformed into an appropriate form by using the Boolean compositions when the equivalence relation is satisfied.

Analytical Modeling of Dual Winding Surface-mounted Permanent Magnet Synchronous Machine for Hybrid Electric Vehicle Accessory Drive Systems

In this chapter, the basic principles of optimization and the mathematical formulation of the optimization problem have been provided. Besides, the categorization of the optimization problems has been presented in terms of the number of constraints, the structure of the variables, and linearity of the formulation elements. Considering the most familiar type of optimization problem, linear optimization approach has been examined in details. Then, some remarkable optimization techniques under the classification of unconstrained and constrained techniques have been investigated. Moreover, as regarding the increasing trend in the utilization of intelligent constrained optimization methods for the implementation and operational problems of renewable energy technologies, the literature have been reviewed.

Symbolic pole assignment of 2DoF conventional helicopter

Abstract Fast and accurate electromagnetic torque calculation of unconventional Permanent Magnet Synchronous Machines (PMSMs) is very important in order to reduce design effort. Dual winding PMSMs (DWPMSMs) can be categorized as unconventional and commonly available fast design software that usually lacks predicting machine performance. In this study, an analytical modeling approach has been proposed to calculate electromagnetic torque of DWPMSMs, which has motor and generator windings in a single stator core. Conformal mapping is used for the calculation of flux levels at various locations in the machine. Radial and tangential components of flux densities due to magnet and winding are determined analytically. Instantaneous value of electromagnetic torque due to generator or motor windings is calculated by integrating the Maxwell stress tensor in the middle of the air gap. Accuracy of the proposed analytical solution is confirmed with finite element analysis results. For further validation, an experimental setup with a 24-slot 22-pole DWPMSM is used. Experimental results have close agreement with analytical results obtained by conformal transform-based modeling.

Effects of varying diagnostic coverage on functional safety

Unmanned air vehicles and their control is a popular research field. The next decade will determine the control perfection of this vehicles and their role in our daily lives will increase. The major advantages of the unmanned rotor systems can be given as their ability to hang on a particular altitude and their manoeuvre agility to move and escape. Whereas there are many studies of control of drones, quadrotors or conventional helicopter as well as full rank state feedback method, the studies considering combination of these methods are rare. Even in symbolic case it is either not detailed so that it can easily be followed and applied or missing. This study aims to assign the poles of two degree of freedom conventional helicopter. The pole placement method used here is full rank state feedback. Thus, the helicopter model for multi input multi output systems is explained, the stages of the control method are described and they are simulated with in Mathematica. The outputs and stability analysis illustrates the effectiveness of the study.